1. Field of the Invention
The present invention relates to a method and an apparatus for the production of a composite plastic material consisting of oriented polymer filaments and a polymer film web, and more particularly, to the production of a composite material which possesses an improved physical strength and higher tear resistance in comparison with plastic film materials which are not reinforced.
2. Discussion of the Prior Art
In recent times, plastic packaging material and bags have to a large extent supplemented or even supplanted similar articles which are constituted of paper, such plastic products being attractive in appearance to a consumer and frequently less expensive to manufacture. Quite frequently, bags which are formed of a polymer film web material are relatively limited in strength, dependent upon the thickness of the film material and, moreover, are readily subject to uncontrollable tearing which often renders the plastic bags unsuitable for use in the packaging or transporting of sharp-edged objects which may readily cause tears in the walls of the plastic bags.
Plastic bags are frequently produced from extruded tubular polymer film webs, or alternatively, may be produced from a continuous sheet of plastic film which has been extruded through a slot die. However, in order to reinforce the material in order to provide a finished product which is able to withstand higher loads and which is more tear-resistant, for example, when the web is formed into a bag, overwrap or similar item, it is desirable to form a reinforced material by adhesively bonding or laminating filaments to the plastic film web material. Such reinforcements may readily take the shape of either flat tapes or round cross-sectioned filaments which have an adhesive applied thereto and are then suitably adhesively bonded to the film web material so as to form a polymer composite having the desired physical characteristics, prior to such composite being formed into the final product.